commit f43be2a4598cf3a47be9f94f0c28197ed9eae611
author Alex Brainman <alex.brainman@gmail.com> Tue Oct 29 19:55:52 2019 +1100
committer Brad Fitzpatrick <bradfitz@golang.org> Tue Oct 29 15:55:21 2019 +0000
tree c4919b41ef4cce5fca6c8e02186b7a2ae872ac26
parent 195ce5e7f934b923d8fc432cf5a2561f2b334da9

windows/registry: make '-gcflags=all=-d=checkptr' flag work

Mostly replaced [:x] slice operation with [:x:x]. 

This change is copy of CL 203442.

Updates golang/go#34972

Change-Id: I9b725a39aea469bd5669cc1deb3d02a88912843e
Reviewed-on: https://go-review.googlesource.com/c/sys/+/204017
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

windows/registry/value.go

diff --git a/windows/registry/value.go b/windows/registry/value.go
index d332d83..f25e7e9 100644
--- a/windows/registry/value.go
+++ b/windows/registry/value.go
@@ -108,7 +108,7 @@
 	if len(data) == 0 {
 		return "", typ, nil
 	}
-	u := (*[1 << 29]uint16)(unsafe.Pointer(&data[0]))[:len(data)/2]
+	u := (*[1 << 29]uint16)(unsafe.Pointer(&data[0]))[: len(data)/2 : len(data)/2]
 	return syscall.UTF16ToString(u), typ, nil
 }
 
@@ -185,8 +185,7 @@
 			return "", err
 		}
 		if n <= uint32(len(r)) {
-			u := (*[1 << 29]uint16)(unsafe.Pointer(&r[0]))[:]
-			return syscall.UTF16ToString(u), nil
+			return syscall.UTF16ToString(r[:n]), nil
 		}
 		r = make([]uint16, n)
 	}
@@ -208,7 +207,7 @@
 	if len(data) == 0 {
 		return nil, typ, nil
 	}
-	p := (*[1 << 29]uint16)(unsafe.Pointer(&data[0]))[:len(data)/2]
+	p := (*[1 << 29]uint16)(unsafe.Pointer(&data[0]))[: len(data)/2 : len(data)/2]
 	if len(p) == 0 {
 		return nil, typ, nil
 	}
@@ -299,7 +298,7 @@
 	if err != nil {
 		return err
 	}
-	buf := (*[1 << 29]byte)(unsafe.Pointer(&v[0]))[:len(v)*2]
+	buf := (*[1 << 29]byte)(unsafe.Pointer(&v[0]))[: len(v)*2 : len(v)*2]
 	return k.setValue(name, valtype, buf)
 }
 
@@ -329,7 +328,7 @@
 		ss += s + "\x00"
 	}
 	v := utf16.Encode([]rune(ss + "\x00"))
-	buf := (*[1 << 29]byte)(unsafe.Pointer(&v[0]))[:len(v)*2]
+	buf := (*[1 << 29]byte)(unsafe.Pointer(&v[0]))[: len(v)*2 : len(v)*2]
 	return k.setValue(name, MULTI_SZ, buf)
 }